Catheter with direction orientation

ABSTRACT

A regional anesthesia catheter used with a guide such as for example a needle cannula has a distal portion integrally connected to a main portion of the catheter by a junction portion that has a cross-sectional profile different from the distal and main portions, so as to predispose the distal portion of the catheter to move in a given direction when the distal portion is not guided by or constrained by the needle cannula. The cross-sectional profile of the junction portion may be configured in a particular shape, or be constructed to have a flexibility that predisposes the distal portion to bend, curve or move toward a given direction. Once the predisposed direction to which the distal end of the catheter points is known, a physician can readily orient the catheter relative to the needle cannula so that once the distal end of the catheter exits the distal tip of the needle cannula, with the cannula already placed in a position proximate to the desired location to which the distal end of the catheter is to be placed, the physician can readily place the distal end of the catheter at the desired location within the patient. Instead of only one junction portion, a number of portions of a catheter may be configured to bend at a predefined direction. Further, a catheter may be configured to have a cross sectional profile or a predefined flexibility along its entire length that causes the catheter to bend, curve or move in a predefined direction.

FIELD OF THE INVENTION

The present invention relates generally to catheters such as for exampleregional anesthesia catheters including epidural catheters that providelocal anesthesia to a patient and more particularly to a catheter thathas a built-in direction orientation that enhances the movement of thecatheter to a particular location inside the patient.

BACKGROUND OF THE INVENTION

For regional anesthesia, a cathether such as an epidural catheter isused to introduce anesthetic agents to the nerves for example at thespine of a patient. To place a catheter close to the nerve spinalcolumn, an epidural needle such as a Tuohy needle is used by theanaesthesiologist. The Tuohy needle is inserted into the nerve sheath,alongside a nerve plexus of the patient. The Tuohy needle has a sharpdistal end that has a beveled aperture, the sharp distal end adapted toreadily pierce the nerve sheath at the spinal column of the patient.Once the anaesthesiologist believes that she has placed the epiduralneedle at the appropriate location in the patient, she would insert thecatheter into the needle and move the catheter until its distal endextends out from the beveled end of the needle cannula. The catheter isusually marked along its length so that the anaesthesiologist knowsapproximately how much the distal end of the catheter extends beyond thedistal tip of the needle cannula. The direction in which the catheter ismoved inside the patient depends, to a large extent, on the insertionand placement of the needle cannula inside the patient by theanaesthesiologist and the skill of anaesthesiologist in maneuvering thecatheter. Oftentimes, an anaesthesiologist, experienced or not, may havea difficult time maneuvering the distal end of the catheter to thedesired location. As a result, a larger than necessary dose ofanesthetic agent may be required to be delivered to the patient tolocally anaesthetize the patient.

There is therefore a need to provide a catheter that can readily bemaneuvered by the physician to a desired location inside a patient.

SUMMARY OF THE PRESENT INVENTION

To assist a physician or an anaesthesiologist with the placement of acatheter for supplying local anesthetic to a patient, the catheter ofthe instant invention has at a portion proximate to its distal end,whereby anesthetic agent is output to a patient, a cross-sectionalprofile that predefines or predisposes the distal end of the catheter tobe bent or headed to a given direction, once the catheter is no longerconstrained by the guide or needle cannula wherethrough it passes.Conventionally, a catheter usually has a uniform circular crosssectional configuration throughout. For the instant invention, at leastone portion of the catheter, preferably at a distance proximate to thedistal end of the catheter, is configured to have a cross-section, whichmay or may not be circular, that predefines or predisposes the distalend of the catheter to move in a given direction. One of thecross-sectional profiles that may be used is an oval shapedconfiguration that causes, or predisposes, the catheter to be bent inthe direction of the width of the greater cross-section width. Anothersectional profile that may be used at the one portion of the catheter isC-shaped so that the distal end of the catheter is predisposed to bendtoward the direction represented by the open mouth of the C.

In addition to having different cross-sectional profiles, the oneportion that is configured to cause the distal end of the catheter tobend at a distal direction could have a different thickness at a sectionthereof so that, even though from the outside diameter the catheter mayappear to be no different from the rest of the catheter, the insidediameter at the one portion is dimensioned to have thicker and thinnersections so that, once the one portion is outside of the needle cannulaor guide, subject to additional movement, the catheter would tend tobend at a predefined orientation to a given direction, thereby enhancingthe movement of the distal end of the catheter inside the patient.

The instant invention therefore relates to a catheter to be used withand passable through a guide for insertion to a patient. The catheterincludes a tubing that has at least one portion having a cross-sectionalprofile that is configured to bend or orient the tubing in a givendirection so that when the one portion of the tubing extends out of theguide, the tubing is predisposed to be routed or headed in a givendirection.

The instant invention also relates to a combination of a hollow guideand a catheter passably fitted to and moveable along the guide. Thecatheter has a substantially circular cross-sectional profile along itsentire length except for at least one portion between its distal andproximal ends. This one portion has a cross-sectional profile configuredto predispose the distal end of the catheter toward a given direction soas to cause the catheter to move toward the given direction once the oneportion of the catheter is no longer constrained by the guide.

The instant invention further relates to a catheter that has a distalportion connected to a main portion by a junction that has across-section that is different from the respective cross-sections ofthe main and distal portions. The distal portion, if unguided, points toand is movable along a first direction; and the main portion, ifunguided, would point to and is movable along a second direction not inalignment with the first direction. The catheter is insertable into andmovable along a hollow guide extending along a given axis. The junctionthat connects the distal portion with the main portion is configured tohave a cross-sectional profile that causes the distal portion to bend orhead toward the first direction once the distal portion and the junctionare no longer confined within the guide after the catheter has beeninserted to the guide and moved therealong.

The instant invention yet further relates to an apparatus that comprisesa needle cannula and a regional anesthesia catheter such as an epiduralcatheter having a distal end and a proximal end. The catheter is movablyfitted to the cannula with its distal end being inserted first into thefirst end of the cannula so that the catheter is movable along thecannula. The catheter has a substantially circular cross-section alongits entire length except for at least one portion proximate to itsdistal end. This one portion has a non-circular cross-section configuredto cause the distal end of the catheter to move in a directionpredefined by the configuration of the one portion when the distal endand then the one portion of the catheter exit outside the cannulathrough its distal end.

The instant invention moreover relates to a method for introducing acatheter into a patient in which a hollow cannula is provided. Thecatheter has at least one portion between its distal and proximal endsthat is configured to cause the distal end of the catheter to bepredisposably moved toward a direction not in alignment with the cannulawhen the one portion is not confined within or constrained by thecannula. The cannula is inserted into the patient proximate to alocation where anesthesia is desired. A catheter is inserted into andmoved along the cannula. The distal end of the catheter is firstinserted into the cannula. Thereafter, the catheter is continuouslymoved into the cannula until at least the one portion of the catheter isextended beyond the distal end of the cannula to predisposedly move thedistal end of the catheter to the desired placement within the patient.

Another embodiment of the instant invention features a catheter such asfor example a regional anesthesia catheter that has a cross sectionalprofile that extends longitudinally along the entire length of thecatheter. The cross sectional profile is configured to cause thecatheter to move in a predefined direction. In particular, the catheterof this embodiment comprises a tubing passable through a guide forinsertion into a patient, the tubing having a given length and the crosssectional profile of the tubing along its entire length is configured tocause the catheter to bend, curve or move in a given direction.

The cross sectional profile of the catheter of the instant invention atthe one portion as noted above or along the entire length of thecatheter may be configured to be oval shaped or C shaped, or othernon-circular shapes for example. The cross sectional profile may also beconfigured to be partially concaved inwards toward the center axis ofthe catheter or tubing, or may have a section of the wall where itsthickness is different from that of the rest of the catheter.

It is therefore an objective of the instant invention to provide acatheter that is configured to be moved in a predisposed directioninside the patient.

BRIEF DESCRIPTION OF THE FIGURES

The present invention will become apparent and the invention itself willbe best understood with reference to the following description of thepresent invention taken in conjunction with the accompanying drawings,wherein:

FIG. 1 is a plan view of the catheter system of the instant inventionshowing a guide in the form of a needle cannula such as an epiduralneedle, and the regional anesthesia catheter of the instant inventionthat is to be fitted into and passes through the needle cannula;

FIG. 2 is the cross-sectional view at A-A of the catheter of the instantinvention;

FIG. 3 is the cross-sectional view B-B of the catheter of the instantinvention;

FIG. 4 is another cross-sectional view at B-B of the catheter of theinstant invention;

FIG. 5 is yet another cross-sectional view at B-B of the catheter of theinstant invention;

FIG. 6 is a plan view showing the distal end of the catheter of theinstant invention having been extended outside the distal tip of theneedle cannula through which the catheter of the instant invention isfitted and guidedly moved; and

FIG. 7 is a plan view of another embodiment of the instant inventioncatheter where the catheter is configured to have a cross sectionalprofile along its entire length that predisposes the entire catheter tobe move in a predefined direction.

DETAILED DESCRIPTION OF THE INVENTION

With reference to FIG. 1, a hollow guide in the form of a regionalanesthetic needle such as for example an epidural needle 2 is shown toinclude a cannula 4 that has a beveled distal tip 6 having an aperture,not shown. Cannula 4 extends from distal tip 6 to, and through, a needlehub 8, which for discussion purposes may be considered to be theproximal end of needle cannula 4. Needle 2 may be a Tuohy needle, butnot necessarily so for the operation and understanding of the instantinvention. Needle hub 8 is made of a rigid plastic that enables theanesthesiologist to manipulate the needle cannula for insertion into apatient, for example into the nerve sheath, alongside a nerve plexus ofthe patient.

Although FIG. 1 illustrates an apparatus that comprises an epiduralcatheter and a needle guide in the form of an epidural needle cannula,it should be appreciated that the instant invention is not limited toepidural catheters. Rather, the instant invention is directed toregional anesthetic catheters which may include, but not limited to,Peripheral Nerve Block catheters, Vascular Access catheters, CVcatheters, PICC (Peripherally Inserted Central Catheters) lines,Ureteral catheters, IVF catheters, Oocyte Recovery Suction catheters andCardiac catheters.

Conventionally, a regional anesthesia catheter, such as for example theepidural catheter shown in the embodiment of FIG. 1, has a circularcross-section such as that shown in FIG. 2. Prior to the instantinvention, to move a catheter to a desired location within a patient,after a needle cannula has been properly inserted into the patient, thephysician has to manipulate the proximal portion of the catheter so asto gently guide the distal end of the catheter to the desired locationin the patient. This manipulation of the catheter oftentimes requires anumber of trials, even for experienced practitioners. Even when thephysician is able to view the catheter, for example via an ultrasoundviewing monitor, the placement of the distal end of the catheternonetheless entails some degree of difficultly. This is possibly due tothe fact that the distal end of the catheter, when inside the patient,would usually follow or go in the direction of the least resistance, asthe physician moves the catheter.

Cannula 4 is adapted to receive a catheter 10. Catheter 10, which has adistal end 12 and a proximal end 14, is inserted into cannula 4 via itsdistal end 12 to the opening (not shown) formed by cannula 4 at hub 8.Catheter 10 is moved so that its distal end 12 passes through cannula 4,exiting at the latter's distal tip 6. Catheter 10 may be manufacturedfrom materials such as but not limited to: nylon including polyamides,Teflon, PVC, urethane, silicone and polyolefins such as polypropylene,polyethylene and polybutylene.

In FIG. 1, catheter 10 is shown to include a distal portion 13 and amain portion 15 that are integrally connected by a junction portion 16.Portion 16 is located proximate to distal end 12 and has a cross-sectionthat is different from the rest of the catheter, i.e., from both distalportion 13 and main portion 15. Distal portion 13 may be considered toextend from distal end 12 of catheter 10 to portion 16 while mainportion 15 of catheter 10 may be considered to extend from portion 16 toproximal end 14 of the catheter. Albeit only one portion 16 is shown inthe catheter of FIG. 1 embodiment, in practice, a number of portions 16may be effected along the length of catheter 10 so that differentpredefined bends or curves may be configured in a single catheter.

When confined within a hollow guide, such as for example needle cannula4, both the distal portion 13 and the main portion 15 of the catheter,being constrained by the cannula, are in alignment along thelongitudinal axis defined by the needle cannula. However, when notconfined or constrained, distal portion 13 of catheter 10 of the instantinvention is not in alignment with its main portion 15, as portion 16 isconfigured to predisposedly position distal portion 13 out of alignmentwith main portion 15 of the catheter 10. Portion 16 of catheter 10 mayalso be configured to have a given flexibility that allows distalportion 13 and main portion 15 of catheter 10 to align alongsubstantially the same longitudinal axis, so long as distal end 12 ofcatheter 10 does not come into contact with any obstruction. In otherwords, portion 16 may be configured to flexibly bend in a predisposeddirection relative to main portion 15 of catheter 10 when distal portion13 encounters an obstruction. Although shown as being only a part ofcatheter 10, portion 16 may in some iterations include the entirecatheter.

As noted above, portion 16 of catheter 10 is configured to have across-sectional profile that is different from the rest of the catheter.For the FIG. 1 embodiment, the cross-section profile, per view B-B, maybe in the shape of an oval, as shown in FIG. 3. With the oval shapedcross-section at portion 16, distal end 12 of catheter 10 is predisposedto move in either direction 18 a or 18 b, rather than 20 a or 20 b.Thus, in practice, when distal end 12, and then portion 16, of thecatheter are moved beyond distal tip 6 of cannula 4, depending on theorientation of catheter 10, as it is being manipulated by theanesthesiologist, distal end 12 of the catheter may either go to thedirection as indicated by 18 a or the direction as indicated by 18 b.This movement of distal end 12 in a given direction may be governed bythe distal tip 6 of needle cannula 4 to a certain extent, as well as theorientation of catheter 10 as it was initially inserted into cannula 4.

In the event that obstruction is encountered, distal end 12 would bendin either direction 18 a or direction 18 b, depending on the orientationof the catheter, and the flexibility of the catheter at portion 16.Portion 16 of the catheter, which may be made from polyamide, may have adifferent thickness than that of the rest of the catheter. Thedifference in thickness may be effected during the extrusion process bystretching portion 16 more than the rest of the catheter. To effect anoval shape, portion 26 may be compressed by an appropriate tool afterthe catheter has been extruded or during extrusion. In any event, toeffect the predisposed bending of the distal end 12 of the catheterrelative to the remaining portion of the catheter, portion 16 may have alength from approximately 3 mm to 15 cm, depending on the length of thecatheter.

FIG. 4 shows another cross-sectional profile for portion 16 of catheter10 of the instant invention. As shown, portion 16 has a cross-section ina shape of a C in which a section 22 of the catheter is constructed tohave a concave shape toward the center of the catheter. As aconsequence, distal end 12 tends to bend in the direction as shown bydirectional arrow 24. Depending on the flexibility built into portion16, the bend may be a built-in curve where distal end 12 would not liein alignment with the remainder portion of the catheter even when thecatheter is not confined within a hollow guide such as for exampleneedle cannula 4. Alternatively, the bend may be such that it only bendstoward direction 24 when obstruction is encountered.

FIG. 5 shows yet another cross-sectional profile of portion 16 of thecatheter of the instant invention. In this embodiment, the cross-sectionis configured to be thicker at section 26 and thinner at section 28. Asa consequence, section 28 is more flexible, or pliable, than section 26at portion 16. Thus, for the embodiment of FIG. 5, distal end 12 of thecatheter is predisposed to move in the direction as indicated bydirectional arrow 30.

FIG. 6 shows the apparatus of the instant invention in which catheter 10has been inserted into epidural needle 2 and moved such that its distalend 12 and portion 16 extend out of distal tip 6 of cannula 4. No longerbeing constrained by cannula 4, for the embodiment shown in FIG. 6,distal end 12 of catheter 10 curves toward the direction indicated bydirectional arrow 32, due to portion 16 having been configured to have across-sectional profile that predisposes distal end 12 to point towarddirection 32, once distal end 12 and portion 16 are no longer confinedwithin cannula 4.

In operation, a physician is provided with a hollow guide, such asneedle cannula 4. The cannula is inserted into the patient proximate toa desired location where the catheter is to be placed. The catheter, andmore particularly the distal end of the catheter, is inserted into theneedle cannula and moved therealong, so that distal portion 13, portion16, and main portion 15 of catheter 10 are confined within the cannulaand are therefore in alignment along the longitudinal axis of thecannula. The catheter is moved further until distal end 12, and thenportion 16, exit distal tip 6 of cannula 4. The orientation of distalend 12 of catheter 10, relative to cannula 4, is rotatably adjusted ororiented by the physician prior to her inserting the catheter into thecannula so that the distal end of the catheter would exit from thedistal tip of the cannula in the direction of the desired location inthe patient.

FIG. 7 is a plan view illustrating another embodiment of the catheter ofthe instant invention. Insofar as the needle cannula to be used with thecatheter of the FIG. 7 embodiment is the same as the needle cannulashown in FIG. 1, no further discussion thereof is needed.

For the catheter 34 of the FIG. 7 embodiment, note that the entirelength of the catheter is configured, per cross-section view C-C, with across-sectional profile that may be represented, for example, by any oneof the profiles shown in FIGS. 3, 4 and 5. In addition to, or as analternative of, the catheter of FIG. 7 may have along its entire lengtha section configured to have a flexibility characteristic that isdifferent from the other sections of the catheter. With any one of thenon-circular cross-sectional profiles as shown in FIGS. 3-5 and/or theflexible cross-section, catheter 34, as shown in FIG. 7, may have anaturally curved or biased orientation, even when the catheter is atrest and not being constrained or confined within the needle cannula 4.Putting it differently, catheter 34 of the FIG. 7 embodiment isconfigured to bend or move in the predefined direction as indicated bydirectional arrow 36. Thus, when catheter 34 is inserted into needlecannula 4, assuming that it remains oriented in the position as shown inFIG. 7, when it is moved by the physician and its distal end exitsdistal tip 6 of needle cannula 4, catheter 34 would move in thedirection designated by directional arrow 40, as the distal portion ofcatheter 34, shown by dotted line, is naturally biased to and thereforeis movable in the predefined direction. Catheter 34 thereby enabling thephysician to readily place the distal end 38 of the catheter at thedesired location within the patient for the supplying the anestheticagent to the patient.

Although the catheter of the instant invention has been described thusfar as used for supplying an anesthetic agent to a patient, it should benoted that other treatment agents may also be supplied via the inventivecatheter. Such other treatment agents may include for example electricalenergy, radio frequency (RF), microwave and ultrasound waves that may betransmitted by the catheter. In the case of electrical energy, it isenvisioned that the catheter may be imbedded with an electricalconductive material such as carbon or includes a wire extending alongits length.

It should be appreciated that the present invention is subject to manyvaraitions, modifications and changes in detail. Thus, it is theintention of the inventor that all matters described throughout thisspecification and shown in the accompanying drawings be interpreted asillustrative only and not in a limiting sense. Accordingly, it isintended that the invention be limited only by the spirit and scope ofthe hereto appended claims.

1-24. (canceled)
 25. Apparatus comprising a needle cannula, ananesthesia catheter having a distal end and a proximal end, saidcatheter movably fitted to said cannula with its distal end beinginserted first into a first end of said cannula so that said catheter ismovable along said cannula, said catheter having a substantiallycircular cross section along its entire length except for at least oneportion proximate to its distal end, said one portion having anon-circular cross section configured to cause the distal end of saidcatheter to move in a direction predefined by the configuration of saidone portion when the distal end and then said one portion of saidcatheter exit outside said cannula through a second end of said cannula.26. A catheter comprising a tubing passable through a guide forinsertion into a patient, said tubing having a given length and a crosssectional profile along the length of said tubing configured topredispose said catheter to bend or curve in a given direction. 27.Catheter of claim 26, wherein the cross sectional profile of saidcatheter is oval shaped.
 28. Catheter of claim 26, wherein the crosssectional profile of said catheter is C shaped.
 29. Catheter of claim26, wherein the cross sectional profile of said catheter is partiallyconcaved inwards-toward the center axis of said tubing.
 30. Catheter ofclaim 26, wherein the cross sectional profile of said catheter isnon-circular.
 31. Cather of claim 26, wherein the cross sectionalprofile of said catheter has at least one section along its longitudinalaxis that has a wall thickness less than that of the rest of saidcatheter.
 32. Apparatus comprising a needle cannula, a regionalanesthesia catheter having a distal end and a proximal end, saidcatheter movably fitted to said cannula with its distal end beinginserted first into a first end of said cannula so that said catheter ismovable along said cannula, said catheter having a cross sectionalprofile along its entire length configured to cause the distal end ofsaid catheter to move in a predefined direction when the distal end andthen the rest of said catheter exit outside said cannula through asecond end of said cannula.
 33. Apparatus of claim 33, wherein saidcatheter has a non-circular cross section.
 34. Apparatus of claim 33,wherein the cross sectional profile of said catheter is oval shaped. 35.Apparatus of claim 33, wherein the cross sectional profile of saidcatheter is C shaped.
 36. Apparatus of claim 33, wherein the crosssectional profile of said catheter is partially concaved inwards towardthe center axis of said tubing.
 37. Apparatus of claim 33, wherein thecross sectional profile of said catheter has at least one section alongits longitudinal axis that has a wall thickness less than that of therest of said catheter.
 38. A catheter to be used with and passablethrough a guide for insertion to a patient, comprising a tubing having across-sectional profile that is configured to bend in a given directionso that when any portion of said tubing extends out of said guide, saidtubing is routed naturally in said given direction.
 39. Catheter ofclaim 38, wherein the cross-sectional profile of said tube is ovalshaped.
 40. Catheter of claim 38, wherein the cross-sectional profile ofsaid tube is C-shaped.
 41. Catheter of claim 38, wherein thecross-sectional profile of said tube is partially concaved inwardstoward the center axis of said tubing.